I have taken a number of cruises in the past (Norwegian Cruise Lines, Princess Cruise Lines, Disney Cruise Lines, Royal Caribbean and now Carnival.)
We were talked into upgrading to the "Owner's Suite" which cost $700/day. Since this was a special occasion we decided to take the upgrade. Big mistake!
Using a scale of 1 = terrible to 10 = unbelievably good I would rate the different lines thus.
Cabin was nice looking and much larger than any other onboard BUT, extremely noisy. We never got a good night's rest.